Side air bag-carrying seat structure

ABSTRACT

In a seat structure having a side air bag device, a longitudinal groove (36) is formed in a seat back pad (14) along the longitudinal direction of the seat back pad, and an insert wire (40) which holds a seat outer cover, is embedded in the longitudinal groove (36). Bent portions (44) are formed in portions of the insert wire (40), which portions oppose the air bag device. Each of the bent portions (44) is bent in a substantially U-shaped configuration, and a slab pad (46) is wound around an outer peripheral portion of a base portion (44A) of each bent portion. Further, the bent portions (44) of the insert wire (40) are each provided to extend rearwardly and diagonally toward the inner side of a seat back (10) so that the embedded length of the insert wire (40) embedded in the seat back pad (14) is made longer, and adverse influences on riding comfort are thereby suppressed.

This application is the national phase of international applicationPCT/JP97/03070 filed Sep. 2, 1997 which designated the U.S.

BACKGROUND ART

There have conventionally been considered counterplans for improvementof an occupant protecting ability at the time of a side surface impact(hereinafter, "side impact") of a vehicle. In recent years, thebuilding-in of a side-impact air bag device at a side portion of a frontseat of a vehicle has been promoted. A structure of this type of frontseat having a side-impact air bag device built-in is disclosed inJapanese Patent Application Laid-Open (JP-A) No. 6-64491. The structuredisclosed therein will be described hereinafter, focusing on therelation between the seat outer cover and the air bag device.

FIG. 8 shows a side view of a front seat 150 having an air bag devicebuilt-in and disclosed in the above prior art. As shown in this figure,a side-impact air bag device 154 is built-in in a side portion, toward adoor, of a seat back 152 of the front seat 150. The side-impact air bagdevice 154 is structured to basically include a sensor 157 disposedbelow a seat cushion 156 and detecting a state of a large load beingapplied to a side door (not shown), a substantially cylindrical inflator158 connected to the sensor 157 and ejecting gas by the sensor 157detecting a state in which a large load is applied, and a bag 160 whichinflates due to gas ejected from the inflator 158. Further, as shown inFIG. 9, the inflator 158 and the bag 160 are accommodated in an internalspace formed by an air bag case 164 and a lid 166 which are fixed to aside portion, toward the door, of a seat back frame 162.

Further, in the structure disclosed in the above prior art, an outercover 168 of the seat back 152 is formed by stitching a plurality ofdivided portions so as to allow an opening movement of the lid 166 atthe time the bag inflates. Namely, the outer cover 168 of the seat back152 is divided into a front main outer cover 170 which covers a frontsurface of a central portion of the seat back 152, two front side outercovers 172, 174 which cover respective front sides of side portions ofthe seat back 152, a seat back side portion outer cover 176 which coversthe lid 166 of the air bag device 154, and a rear outer cover 178 whichcovers a back side of the seat back 152.

In order to allow opening of the seat back side portion outer cover 176located at the side of the lid 166, a front end portion 176A of the seatback side portion outer cover 176 and a rear end portion 174A of thefront side outer cover 174 are sewn together by a sewing thread 180. Thesewing strength at the above sewn-together portion is set to be low bysewing by single stitching as shown in FIG. 9. Accordingly, thissewn-together portion is used as a rupture portion. In contrast, a rearend portion 176B of the seat back side portion outer cover 176 and afront end portion 178A of the rear outer cover 178 are each formed intoa loop and are stitched by using sewing threads 182, 184, and further,the loop-shaped rear end portion 176B and front end portion 178A aresewn together by a sewing thread 186. The sewing strength at thissewn-together portion is set to be high by sewing by double stitching asshown in FIG. 9. Accordingly, this sewn-together portion does notrupture, and serves as a hinge used for the opening movement of the seatback side portion outer cover 176.

Accordingly, when the bag 160 unfolds due to gas ejected from theinflator 158, the lid 166 opens toward an outer side of the seat (i.e.,in the direction indicated by arrow W in FIG. 9) around a hinge portion166A formed at the rear end of the lid 166. Due to the opening force ofthe lid 166, the portion where the front end portion 176A of the seatback side portion outer cover 176 and the rear end portion 174A of thefront side outer cover 174 are sewn together is broken.

However, in this seat structure having a side air bag device, an insertwire 192 is embedded in a seat back pad 190 in the vicinity of anoccupant supporting surface (top plate portion) 190A. A sewn-togetherportion of the front main outer cover 170 and the front side outer cover172 is engaged with the insert wire 192 via a hanging member 188 forbringing forth the designed seat configuration. Accordingly, at aninitial stage of unfolding of the bag 160, a pull-out load acts on theinsert wire 192 due to reactive force of the seat outer cover 168 causedby the unfolding force of the bag 160. When the pull-out load increasesand the insert wire 192 is thereby pulled out from the seat back pad190, the outer cover 168 extends greatly outward in the transversedirection of the seat and toward the front of the vehicle as indicatedby the two-dot chain line in FIG. 9. For this reason, the sewn-togetherportion formed by the sewing thread 180, which was originally intendedto be broken, is difficult to break. Accordingly, the unfolding speed ofthe bag 160 may decrease or the unfolded form of the bag 160 may beunstable.

As art related to the present invention, Japanese Patent ApplicationLaid-Open (JP-A) No. 9-76868 (laid-open on Mar. 25, 1997) discloses anend of a front-side seat outer cover of a sewn-together portion to bebroken and a seat-side fixing member being connected together by astrong cloth.

DISCLOSURE OF THE INVENTION

In view of the above-described facts, it is an object of the presentinvention to provide a seat structure having a side air bag device whichprevents pull-out of an insert wire and allows rapid and stableunfolding of a side-impact air bag body.

In accordance with the present invention, there is provided a seatstructure having a side air bag device, in which a seat having a sideair bag device built-in is covered with a seat outer cover, wherein aninsert wire, which holds a hanging member for bringing forth thedesigned seat configuration, is embedded in a vehicle occupantsupporting surface of a seat back pad, and means for preventing pull-outof the insert wire is provided at a portion of an embedded portion ofthe insert wire embedded in the seat back pad. As a result, at the timeof a side impact of a vehicle, an air bag body accommodated in the airbag device expands to push the seat outer cover from the inner side ofthe seat. The insert wire is thereby about to be pulled out from theseat back pad via the hanging member for bringing forth the designedseat configuration. Due to the pull-out preventing means which isprovided at a portion of an embedded portion of the insert wire embeddedin the seat back pad, load which causes the insert wire to be pulled outfrom the seat back pad increases to prevent pull-out of the insert wire.And, rising up of a top plate portion of the seat outer cover isprevented. As a result, the seat outer cover is broken rapidly from apredetermined sewn-together portion, and rapid and stable unfolding ofthe air bag body can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view which shows a half, at the side of a side door ofa vehicle, of a seat back pad of a seat structure having a side air bagdevice according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along line 2--2 in FIG.3.

FIG. 3 is a perspective view which shows a seat to which the seatstructure having a side air bag device according to the first embodimentof the present invention is applied.

FIG. 4 is a front view which shows a half, at the side of a side door ofa vehicle, of a seat back pad of a seat structure having a side air bagdevice according to a modified example of the first embodiment of thepresent invention.

FIG. 5 is a front view which shows a half, at the side of a side door ofa vehicle, of a seat back pad of a seat structure having a side air bagdevice according to another modified example of the first embodiment ofthe present invention.

FIG. 6 is a front view which shows a half, at the side of a side door ofa vehicle, of a seat back pad of a seat structure having a side air bagdevice according to a second embodiment of the present invention.

FIG. 7 is a cross-sectional view, corresponding to FIG. 2, of the seatstructure having a side air bag device according to the secondembodiment of the present invention.

FIG. 8 is a schematic side view which shows a seat structure having aside air bag device according to a conventional example.

FIG. 9 is a horizontal cross-sectional view which shows a side portionof the seat structure having a side air bag device according to theconventional example.

BEST MODE FOR IMPLEMENTING THE INVENTION

A description will be hereinafter given of a seat structure having aside air bag device according to a first embodiment of the presentinvention with reference to FIGS. 1 to 3.

As shown in FIG. 2, a seat back 10 of the seat according to the firstembodiment of the present invention includes a seat back frame 12 whichforms a frame member of the seat back and has a substantiallyrectangular frame shape, a seat back pad 14 mounted at the front side ofthe seat back frame 12 and set to a predetermined hardness by usingurethane resin or the like, and a seat back outer cover 16 which coversthe surface of the seat back pad 14.

As shown in FIG. 3, a side-impact air bag device 18 is built-in in aside portion 10A, toward a side door of a vehicle, of the seat back 10.

As shown in FIG. 2, the air bag device 18 is fixed to a side portion 12Aof the seat back frame 12 and is a commonly known device provided toinflate and unfold an air bag body by an inflator. Therefore,description and illustration of the component parts of the air bagdevice 18 will be omitted.

A lid 22 is disposed at the side-impact air bag device 18 at a positionfacing the side door of the vehicle. When the air bag body unfolds, thelid 22 opens toward an outer side of the seat (i.e., in the directionindicated by arrow A in FIG. 2).

A seat back outer cover 16 is divided into a plurality of portions.Specifically, the seat back outer cover 16 is divided into a front mainouter cover 24, a front side outer cover 26, and a seat back sideportion outer cover 28. The front main outer cover 24 forms a portion ofa front surface seat outer cover and covers a front surface of thecentral portion of the seat back pad 14, the front side outer cover 26forms a portion of the front surface seat outer cover and covers a frontsurface of the side portion of the seat back 10, and the seat back sideportion outer cover 28 forms a side surface seat outer cover and coversa side surface of the side portion of the seat back 10.

The seat outer cover 16 has a three-layer or five-layer structure inwhich a cushioning material is held between two sheets of clothmaterials.

A front end 28A of the seat back side portion outer cover 28 and anouter end 26A of the front side outer cover 26 are sewn together by asewing thread 30. A sewn-together portion 31 of the front end 28A of theseat back side portion outer cover 28 and the outer end 26A of the frontside outer cover 26 is positioned at the front side of and in thevicinities of front edge portions of the lid 22 and the air bag body.The sewn-together portion 31 is formed as a sewn-together portion to bebroken by the lid 22 when the air bag body inflates.

An inner end 26B of the front side outer cover 26 and a hanging cottoncloth member 32, which has a loop-shaped cross-sectional configurationand is formed as a hanging member for bringing forth the designed seatconfiguration, are sewn to an outer end 24A of the front main outercover 24 by a sewing thread 34. Further, the sewn-together portionformed by the sewing thread 34 and the hanging cotton cloth member 32are inserted into a vertical groove 36 formed in the seat back pad 14along the vertical direction (up and down directions). The front sideouter cover 26 and the front main outer cover 24 are caught by an insertwire 40 embedded in a bottom portion of the longitudinal groove 36 viathe cotton cloth member 32 and a C-shaped ring 38 attached to thehanging cotton cloth member 32.

As shown in FIG. 1, concave portions 42 are formed in the bottom portionof the vertical groove 36 along the vertical direction at predeterminedintervals, and the insert wire 40 is exposed in the concave portions 42.For this reason, in the concave portions 42, the C-shaped ring 38 ishooked on the insert wire 40.

Bent portions 44 formed by the insert wire 40 being bent convexly areprovided as a pull-out preventing means at respective positions, facingthe air bag device 18 (see FIG. 3), between top and second concaveportions 42 from the top and between the second and third concaveportions 42. Each of the bent portions 44 is formed to have asubstantially U-shaped configuration, and a slab pad 46 serving aswinding means (pull-out preventing means) is wound around an outerperipheral portion of a base portion 44A of each bent portion 44. Thematerial for the seat back pad 14 is impregnated into the slab pad 46and foams.

As shown in FIG. 2, the bent portions 44 of the insert wire 40 areprovided to extend rearwardly and diagonally toward the inner side ofthe seat back 10. As a result, the embedded length of the insert wire 40embedded in the seat back pad 14 is made longer, and adverse influencesexerted on riding comfort are suppressed.

As shown in FIG. 1, a bent portion 48 is formed at an upper end portionof the insert wire 40. The bent portion 48 is formed in the shape of aloop and extends in the same direction as the direction in which thebent portions 44 extend. Further, respective lower end portions of theinsert wires 40 provided at the left and right sides of the seat back 10are connected to each other by a connecting portion 50 extending alongthe transverse direction of the seat back 10.

As shown in FIG. 2, a cotton cloth member 52 which is more difficult toextend than the seat outer cover is disposed at an inner side of theseat back side portion outer cover 28. A front end 52A of the cottoncloth member 52 is sewn provisionally to a front end 28A of the seatback side portion outer cover 28 by a provisionally sewing thread 54,and is also sewn by the sewing thread 30 to the front side outer cover26 together with the seat back side portion outer cover 28 at a positionat an outer side of the provisionally sewing thread 54.

A rear end 52B of the cotton cloth member 52 is engaged via a hook 58with a wire 58 serving as a seat-side fixing member and provided in theseat back frame 12. Further, a rear end 28B of the seat back sideportion outer cover 28 is hooked by the C-shaped ring 38 on a wire 58provided in the seat back frame 12 in such a manner that a hanging wire60 passes through a loop-shaped cotton cloth member 55. In FIG. 2,reference numeral 62 designates a portion of a backboard mounted on therear surface of the seat back.

Next, operation of the first embodiment of the present invention will bedescribed.

In the seat structure having a side air bag device according to thefirst embodiment of the present invention, when an inflator of the airbag device 18 is actuated at the time of a side collision of a vehicle,the air bag body inflates due to gas ejected from the inflator to pushthe lid 22 of an air bag case open in the direction indicated by arrow Ain FIG. 2.

In this case, the cotton cloth member 52 is provided at the inner sideof the seat back side portion outer cover 28, and the rear end 28B ofthe seat back side portion outer cover 28 and the rear end 52B of thecotton cloth member 52 are respectively connected to the wires 60, 58via the cotton cloth member 55 and the hook 56. For this reason, stresscaused by expansion of the air bag body concentrates at thesewn-together portion 31 via the cotton cloth member 52.

Further, in the seat structure having a side air bag device according tothe first embodiment of the present invention, the substantiallyU-shaped bent portions 44, the bent portion 48, and the connectingportion 50 are formed at the insert wire 40 and the embedded length ofthe insert wire 40 embedded in the seat back pad 14 thereby increases.For this reason, the insert wire 40 is not pulled out from the seat backpad 14 due to reactive force of the front side outer cover 26.

Accordingly, the seat structure having a side air bag device accordingto the first embodiment of the present invention can suppresspulling-out of the insert wire 40 and cause the sewn-together portion 31to be instantaneously broken so as to allow rapid and stable unfoldingof the side-impact air bag body.

Further, in the seat structure having a side air bag device according tothe first embodiment of the present invention, the slab pad 46 is woundaround the outer periphery of the base portion 44A of each bent portion44 of the insert wire 40, and therefore, it is even more difficult pullout the insert wire 40 from the seat back pad 14.

Moreover, the seat structure having a side air bag device according tothe first embodiment of the present invention is provided such that thebent portions 44 of the insert wire 40 extend rearwardly and diagonallytoward the inner side of the seat back 10. For this reason, adverseinfluences of the insert wire 40 on riding comfort can be suppressed.

In addition, in the seat structure having a side air bag deviceaccording to the first embodiment of the present invention, respectivelower ends of the insert wires 40 disposed at the left and right sidesof the seat back are connected to each other by the connecting portion50 extending along the transverse direction of the seat back. However,alternatively, as shown in FIG. 4, the insert wires 40 disposed at theleft and right sides of the seat back may be separated from each other,and respective lower end portions 49 of the insert wires 40 may each beformed in the shape of a loop.

Further, in the first embodiment of the present invention, there wasdescribed a so-called longitudinal hanging type seat structure in whichthe seat back outer cover 16 is hung up and supported by the insertwires 40 embedded along the vertical direction of the seat back pad 14.However, the seat structure having a side air bag device according tothe present invention can be, as shown in FIG. 5, also applied to aso-called transverse hanging type seat structure in which the seat backouter cover is hung up and supported by an insert wire 66 embedded in abottom portion of a transverse groove 64 formed along the transversedirection of the seat back pad 14. In FIG. 5, a concave portion 65 isformed in the transverse groove 64, a bent portion 68 is formed at anend portion of an insert wire 66, and a slab pad 70 serving as a windingmember (i.e., pull-out preventing means) is wound around an outerperipheral portion of the bent portion 68.

Next, a seat structure having a side air bag device according to asecond embodiment of the present invention will be described withreference to FIGS. 6 and 7.

It should be noted that the same members as those of the firstembodiment will be denoted by the same reference numerals, and adescription thereof will be omitted.

As shown in FIG. 6, in the seat structure having a side air bag deviceaccording to the second embodiment of the present invention, a throughhole 72 is formed at a position in a vicinity of the vertical directioncentral portion of the air bag device in a bottom portion of a verticalgroove 36 of the seat back pad 14, such that the longitudinal directionof the through hole 72 coincides with the vertical direction of the airbag device.

As shown in FIG. 7, a strong cloth 76 having a loop-shapedcross-sectional configuration and serving as connecting means (i.e.,pull-out preventing means) passes through the through hole 72 in such amanner as to be sewn to the inner end 26B of the front side outer cover26 and the outer end 24A of the front main outer cover 24 by a sewingthread 74. The strong cloth 76 is engaged via a hook 78 with an engagingportion 12B, which serves as a seat-side fixing member, of the seat backframe 12.

Accordingly, in the seat structure having a side air bag deviceaccording to the second embodiment of the present invention, due to thereactive force of the front side outer cover 26 being supported by thewebbing cloth 76 during inflation of the air bag body, the insert wire40 can be prevented from being pulled out from the seat back pad 14. Forthis reason, as compared with the first embodiment, the sewn-togetherportion 31 can be instantaneously broken more effectively, and rapid andstable unfolding of the side-impact air bag body can be achieved.

In the foregoing description, the present invention was described withrespect to specified embodiments. However, the present invention is notlimited to these embodiments, and it will be clear to those skilled inthe art that other variations may be made within the scope of thepresent invention. For example, in the present embodiments, the slab pad46 is used as the winding member, but in place of the slab pad 46,another winding member formed by a felt material or the like may beused.

INDUSTRIAL APPLICABILITY

As described above, the seat structure having a side air bag deviceaccording to the present invention is useful for rapid and stableunfolding of a side-impact air bag body. Specifically, in a seatstructure having a side air bag device built-in at a side portion of aseat back toward a door of a vehicle, the present invention is suitablefor suppressing pulling-out of an insert wire and for rapidly and stablyunfolding the side-impact air bag body.

We claim:
 1. A seat structure having a side air bag device comprising:aseat back pad disposed adjacent to the side air bag device; a seat outercover covering the seat back pad and the side air bag device; and aninsert wire embedded in the seat back pad, wherein portions of the seatouter cover covering the side air bag device are attached at a pluralityof points to the insert wire, and wherein the insert wire betweenadjacent connection points includes a convex bent portion which projectsrearwardly.
 2. A seat structure having a side air bag device accordingto claim 1, wherein the bent portion of the insert wire is provided toextend rearwardly and diagonally toward an inner side of the seat backpad.
 3. A seat structure having a side air bag device according to claim1, further comprising a second insert wire, wherein left and rightlongitudinal grooves are provided in the seat back pad along thevertical direction of the seat back pad, and wherein the first insertwire is embedded in a bottom portion of the left groove and the secondinsert wire is embedded in a bottom portion of the right groove, andrespective lower ends of the insert wires are connected together in thetransverse direction of the seat structure.
 4. A seat structure having aside air bag device according to claim 1, further comprising a secondinsert wire, wherein left and right longitudinal grooves are provided inthe seat back pad along the vertical direction of the seat back pad, andwherein the insert wires are embedded independently in bottom portionsof the left and right grooves and both end portions of each of theinsert wires are each bent in a loop shape.
 5. A seat structure having aside air bag device according to claim 1, wherein the insert wire isembedded in a bottom portion of a transverse groove provided in thetransverse direction of the seat back pad, and an end portion of theinsert wire is bent in a loop shape.
 6. A seat structure having a sideair bag device in which the seat structure having the side air bagdevice is covered with a seat outer cover,wherein an insert wire isembedded in a vehicle occupant supporting surface of a seat back pad ofthe seat structure, and a winding member is provided at a portion of anembedded portion of the insert wire embedded in the seat back pad, so asto allow a material for the seat back pad to be impregnated into theseat back pad and to foam.
 7. A seat structure having a side air bagdevice according to claim 6, wherein at least a section of the insertwire which section opposes the air bag device is bent convexly toward arear side of a vehicle, and the winding member is provided at the bentsection.
 8. A seat structure having a side air bag device, in which theseat structure having the side air bag device is covered with a seatouter cover,wherein an insert wire is embedded in a vehicle occupantsupporting surface of a seat back pad of the seat structure, a throughhole is formed in the seat back pad at a position opposing the air bagdevice, and connecting means connected to the seat outer cover isengaged with a seat-side fixing member via the through hole.
 9. A seatstructure having a side air bag device according to any one of claims 1,4, 6, 7, or 8, wherein a cloth which is more difficult to extend thanthe seat outer cover is provided at a rear surface of a side surfaceseat outer cover, a front end of the cloth is sewn to a sewn-togetherportion to be broken, and a rear end of the cloth is engaged with aseat-side fixing member.